《数学课程标准》指出:“学生的数学学习内容应当是现实的、有意义的、富有挑战性的,这些内容要有利于学生主动地进行观察、实验、猜测、验证、推理与交流等数学活动。内容的呈现应采用不同的表达方式,以满足多样化的学习需求。有效的数学学习活动不能单纯地依赖模仿与记忆,动手实践、自主探索与合作交流是学生学习数学的重要方式。”正是本着这样的理念,笔者在设计《角的初步认识》这一课时,以教材为本,抓住角的特征,充分激发学生的学习兴趣,调动学生的主观能动性,让 The Mathematics Curriculum Standard states: “The mathematics content of students should be realistic, meaningful and challenging, and should be conducive to students' initiative in mathematics such as observation, experiment, speculation, verification, reasoning and communication Activities.Content should be presented in different ways to meet diverse learning needs.Effective mathematical learning activities can not simply rely on imitation and memory, hands-on practice, independent exploration and cooperation and exchange is an important way for students to learn mathematics. It is in this concept, the author in the design of ”the initial understanding of the angle" this lesson, teaching materials, to seize the characteristics of the corner, to fully stimulate students 'interest in learning, mobilize the students' subjective initiative, let